Conveyor systems for diverting objects

ABSTRACT

In one embodiment, a conveyor system includes a conveyor belt having a plurality of conveyor belt rollers configured to divert objects on the conveyor belt, and a drive mechanism that engages the conveyor belt rollers, the drive mechanism being configured to drive the conveyor belt rollers, the drive mechanism being adjustable such that the conveyor belt rollers can be selectively driven in a first angular direction and a second, opposite angular direction so that objects can be selectively diverted to either side of the conveyor belt at a desired diverting angle. One version of the drive mechanism has drive rollers mounted in cartridges and rack gears engaging pinion gears on the cartridges to adjust the orientation of the drive rollers relative to the belt rollers to drive them in selectively opposite angular directions.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation-in-part of U.S. patent applicationSer. No. 11/627,132, “Systems and Methods for Diverting Objects,” filedJan. 25, 2007, now U.S. Pat. No. 7,461,739 which claims priority to U.S.provisional application Ser. No. 60/762,227, “Systems and Methods for aVariable Angle High-Speed Diverting Conveyor System,” filed Jan. 26,2006, both of which are entirely incorporated herein by reference.

BACKGROUND

The invention relates generally to power-driven conveyors and, moreparticularly, to conveyor systems having conveyor belts withobject-supporting rollers rotated by contact with freely rotatable driverollers whose orientations are changeable to cause the object-supportingrollers to rotate in one direction or another.

It is often necessary to divert objects from a conveyor belt, forexample to another conveyor belt, for purposes of routing or positioningthe objects for processing of one type or another.

Recently, conveyor systems have been developed in which the conveyorbelt comprises a plurality of small, angled rollers that extend beyondthe top and bottom surfaces of the belt. With such systems, objectscarried by the conveyor belt, and more particularly by the rollerscontained within the belt, can be diverted from the belt by rotating therollers. The conveyor belt rollers can be caused to rotate using variousmethods. In one such method, the rollers are driven by selectivelybringing a friction plate located beneath the conveyor belt into and outof engagement with the rollers. When the plate engages the rollers, therollers are caused to rotate in response to the frictional forcesbetween the friction plate and the rollers. In another method,free-spinning rollers located below the conveyor belt are selectivelyengaged with and disengaged from the conveyor belt rollers, and frictionbetween the engaged rollers causes rotation of both sets of rollers inopposite directions.

Although the above-described conveyor systems provide significantadvantages in relation to diverting objects from a conveyor belt, somelimitations in their use still exist. For example, because the angles ofthe conveyor belt rollers are fixed, diverting can only be performed toone side of the conveyor belt and at a fixed diverting angle. Therefore,if it is desired to change the diverting direction or angle, theconveyor line must be shut down and the conveyor belt must be replacedwith a different conveyor belt having rollers arranged in a differentorientation.

A further disadvantage relates to roller slip. Specifically, when afriction plate is brought into contact with the rollers, the rollersmust accelerate from zero angular velocity to a final angular velocityproportional to the speed at which the conveyor belt is traveling. Giventhat the rollers cannot instantaneously accelerate to the final angularvelocity, roller slip occurs that causes wear to the rollers. The samephenomenon can occur, albeit to a lesser degree, in embodiments thatemploy free-spinning rollers to rotate the conveyor belt rollers.Specifically, although rotation of the free-spinning rollers reducesslip, slip can still occur during the period just after roller-to-rollercontact is made.

Furthermore, when the friction plate or the free-spinning rollers aredisengaged from the conveyor belt rollers, the conveyor belt rollers arefree to rotate, which can enable objects present on the conveyor belt todrift across the belt. Although such drift may be desirable in somesituations, it may be undesirable in situations in which it is desiredto precisely control the lateral position of an object on the conveyorbelt.

SUMMARY

These disadvantages are overcome by a conveyor system embodying featuresof the invention. One version of such a conveyor system comprises aconveyor belt having a plurality conveyor belt rollers configured todivert objects on the conveyor belt as the conveyor belt advances and aroller drive mechanism. The roller drive mechanism includes rotatablecartridges. Each cartridge has a cartridge gear and a freely rotatabledrive roller that engages the conveyor belt rollers from below theconveyor belt. Actuator gears, each engaged with one of the cartridgegears, rotate the cartridges to change the orientations of the rotatabledrive rollers with respect to the conveyor belt rollers. An actuatorconfigured to move the plurality of actuator gears rotates thecartridges between a first orientation in which the engagement betweenthe drive rollers and the conveyor belt rollers causes the conveyor beltrollers to rotate in a first direction as the conveyor belt advances anda second orientation in which the engagement between the drive rollersand the conveyor belt rollers causes the conveyor belt rollers to rotatein an opposite second direction.

Another version of a conveyor system embodying features of the inventioncomprises a conveyor belt having a plurality conveyor belt rollersarranged to rotate on fixed axes aligned in a direction of belt travel.Cartridges are rotatably supported in openings in a carryway panunderlying the conveyor belt. Each cartridge includes a freely rotatabledrive roller retained in position to engage the conveyor belt rollersfrom below the conveyor belt. A cartridge gear is disposed on thecartridge below the carryway pan. An array of actuator gears ispositioned to engage the cartridge gears. An actuator coupled to thearray of actuator gears actuates the gears to rotate the cartridges andchange the angle of engagement between the drive rollers and theconveyor belt rollers.

Yet another version of a conveyor system comprises a conveyor beltadvancing longitudinally in a direction of belt travel and a rollerdrive mechanism underlying the conveyor belt. The belt has conveyor beltrollers arranged in lateral rows and longitudinal columns. The rollersare rotatable on fixed longitudinal axes. The roller drive mechanismincludes a support plate having openings arranged in columns alignedwith the columns of conveyor belt rollers. Cartridges rotatably receivedin the openings have cartridge gears and drive rollers, which aresupported in position to engage the conveyor belt rollers. A movablegear plate has actuator gears, each of which engages with one of thecartridge gears to rotate the cartridges and the drive rollers as thegear plate is moved.

BRIEF DESCRIPTION OF THE DRAWINGS

The disclosed systems and methods can be understood with reference tothe following drawings. The components in the drawings are notnecessarily to scale.

FIG. 1 is a top perspective view of a first embodiment of a portion of aconveyor system.

FIG. 2A is a top perspective view of a drive roller module used in theconveyor system of FIG. 1.

FIG. 2B is a bottom perspective view of a drive roller module used inthe conveyor system of FIG. 1.

FIG. 3 is top perspective view of a further portion of the conveyorsystem of FIG. 1.

FIG. 4 is a bottom perspective view of a plurality of drive rollermodules used in the conveyor system of FIG. 1.

FIG. 5A is a view of the conveyor system portion shown in FIG. 3,illustrating diverting action in a first direction.

FIG. 5B is a view of the conveyor system portion shown in FIG. 3,illustrating diverting action in a second direction.

FIG. 6A is a top view of a drive roller module, illustrating pivoting ofthe module in a first angular direction.

FIG. 6B is a top view of a drive roller module, illustrating pivoting ofthe module in a second angular direction.

FIG. 7 is an end view of a portion of the conveyor system of FIG. 1,illustrating a braking function provided by angularly adjustable driverollers of the system.

FIG. 8A is an end of a portion of the conveyor system of FIG. 1,illustrating engagement of angularly adjustable drive rollers andconveyor belt drive rollers.

FIG. 8B is an end of a portion of the conveyor system of FIG. 1,illustrating disengagement of angularly adjustable drive rollers andconveyor belt drive rollers.

FIG. 9 is a top perspective view of a second embodiment of a portion ofa conveyor system.

FIGS. 10A-10C are top views of the conveyor system of FIG. 9,illustrating angular adjustment of drive rollers of the system to adjustdiverting angle.

FIGS. 11A and 11B are perspective views of an embodiment of a mechanismthat can be used to adjust the angulation of the drive rollers of theconveyor system of FIG. 9.

FIG. 12 is a detail view of an embodiment of joints that support ends ofdrive rollers in the conveyor system of FIG. 9.

FIG. 13 is an exploded top isometric view of a third embodiment of aportion of a conveyor system with a rack-and-pinion roller drivemechanism.

FIG. 14 is a top exploded isometric view of a drive roller cartridge ofthe conveyor system of FIG. 13.

FIG. 15 is a bottom isometric view of a linear actuator in the rollerdrive mechanism of FIG. 13.

FIGS. 16A and 16B are top plan views of the drive rollers of theconveyor system of FIG. 13 shown in opposite extreme positions.

DETAILED DESCRIPTION

As described above, existing conveyor systems that include conveyor beltrollers, although providing advantages over previous systems, still havelimitations. As described in the following, however, such limitationscan be overcome with a conveyor system that employs a drive mechanismcomprising free-spinning angularly adjustable rollers that controlrotation of rollers contained within a conveyor belt. In someembodiments, a conveyor belt comprises a plurality of longitudinallyoriented free-spinning rollers that are “driven” through contact withfree-spinning angularly adjustable rollers that are positioned below theconveyor belt. In such systems, objects can be diverted at variousangles to either side of the conveyor belt through mere actuation of theangularly adjustable rollers. Furthermore, when the angularly adjustablerollers are aligned with the direction of belt travel, the conveyor beltrollers can be braked such that they will not rotate, thereby reducingor eliminating object drift. Moreover, given that the angularlyadjustable rollers can be gradually rotated from the braking orientationto a desired diverting angle, the conveyor belt rollers can be graduallyaccelerated, thereby reducing or eliminating slip.

Referring to the figures, in which like numerals indicate correspondingparts throughout the several views, FIG. 1 illustrates an embodiment ofa portion of a conveyor system 100 that can be adjusted to divertobjects at various angles to either side of the system. As indicated inFIG. 1, the conveyor system 100 comprises a conveyor belt 102 and afield 104 of angularly adjustable “drive” roller modules 106. In theembodiment of FIG. 1, the conveyor belt 102 comprises a conveyor beltframe 108 that is composed of a plurality of transverse modular conveyorbelt sections 110. Within each conveyor belt section 110 is a pluralityof elongated conveyor belt links 112 that extend in the direction ofbelt travel 114 and connect to adjacent conveyor belt links of adjacentconveyor belt sections. By way of example, each conveyor belt link 112comprises a metal or plastic member having an opening 116 provided ateach of its opposed ends that receives a rod or shaft (not shown) thatpasses through the openings of conveyor belt links of adjacent conveyorbelt sections 110 so as to connect the conveyor belt sections to eachother.

Interposed between the conveyor belt links 112 are elongatedlongitudinally oriented free-spinning conveyor belt rollers 118. For thepurposes of this disclosure, the term “free-spinning” means that therollers are free to spin about their axes of rotation in either angulardirection. Therefore, the rollers 118 may be said to comprise “idler”rollers that will freely rotate in either angular direction when drivenby an appropriate force. In the embodiment of FIG. 1, the rollers 118are positioned such that their axes of rotation are parallel to thedirection of belt travel 114. As shown in FIG. 1, the rollers 118 can bealternately provided along the width of each conveyor belt section 110in relation to the conveyor belt links 112 such that a roller ispositioned between each pair of adjacent conveyor belt links. In such anarrangement, the rollers 118 of the various conveyor belt sections 110can be arranged in columns 120 that extend in the direction of belttravel 114 and rows 121 that extend across the width of the conveyorbelt 102. It is noted that, although the rollers 118 have been describedand depicted as being elongated, the rollers need not necessarily beelongated in the direction of their axes of rotation.

The conveyor belt rollers 118 are made of metal and/or plastic and areprovided with a rubber or plastic high-friction outer layer or coatingthat prevents slippage when rollers of the roller modules 106 arebrought into contact with the conveyor belt rollers. Each roller 118 canconnect at each of its ends to the conveyor belt frame 108 and/or to therods or shafts that connect the various conveyor belt sections 110. Asindicated in FIG. 7, the rollers 118 are dimensioned so as to extendbeyond the upper and lower surfaces of the conveyor belt frame 108 (andbelt links 112) such that they can both divert objects placed on theconveyor belt 102 and can be driven from below by the drive rollermodules 106.

With further reference to FIG. 1, the field 104 of angularly adjustabledrive roller modules 106 comprises a plurality rows 122 and columns 124of drive roller modules. The drive roller modules 106 are positionedsuch that their columns 124 align with the columns 120 of the conveyorbelt rollers 118 and their rows 122, at least intermittently duringconveyor system operation, align with rows 121 of conveyor belt rollers.In the first embodiment shown in FIG. 1, the drive roller modules 106comprise relatively short (in the dimension of their axes of rotation)caster rollers (see FIGS. 2A and 2B) that are positioned closely enoughto each other such that at least one drive roller is aligned with anygiven conveyor belt roller 118 during the operation. Indeed, in theembodiment of FIG. 1, the drive roller modules 106 are positionedclosely enough such that at least two drive rollers are positionedadjacent any given conveyor belt roller 118, during conveyor operation.

Turning to FIGS. 2A and 2B, which illustrate perspective views of asingle drive roller module 106, each drive roller module includes afree-spinning drive roller 125 that is free to rotate in either angulardirection relative to its axis of rotation. Accordingly, althoughdesignated as “drive” rollers, the drive rollers 125 are not themselvesdriven by some mechanical means, such as a motor or the like. By way ofexample, each drive roller 125 is made of metal and/or plastic and, likethe conveyor belt rollers 118, has a rubber or plastic high-frictionouter layer or coating.

As shown in FIGS. 2A and 2B, the drive roller 125 is supported within aframe 126 that comprises opposed vertical support members 128. Extendingbetween the support members 128 and through a central opening providedin the drive roller 125 (not shown) is a shaft 130 about which the driveroller can rotate (i.e., the axis of rotation). In addition to thesupport members 128, the frame 126 comprises first and second controlarms 131 and 132 that, as described below, can be used to pivot thedrive roller module 106 about a central vertical axis 134 to adjust theangle of the roller 125 relative to the direction of belt travel 114(FIG. 1). As indicated in FIGS. 2A and 2B, each control arm 131, 132comprises an opening 133 that enables pivotal connection to anappropriate member that is used to adjust the angular orientation of thedrive roller module 106.

As best shown in FIG. 2B, the frame 126 further includes a base 135 anda pivot mechanism 137 that supports the base. In the embodiment of FIG.2B, the pivot mechanism 137 comprises upper and lower portions 139 and141 that can rotate in opposite directions relative to each other andthereby enable pivoting of the drive roller module 106. Suitablefriction reducing elements, such as bearings, can be provided betweenthe portions 139 and 141 to facilitate such pivoting.

FIG. 3 illustrates a further portion of the conveyor system 100. Moreparticularly, FIG. 3 illustrates interaction between the drive rollers125 and the conveyor belt rollers 118. Notably, the conveyor belt frame108 is not shown in the figure for purposes of clarity in describingother components of the conveyor system 100.

As indicated in FIG. 3, the drive rollers 125 are positioned so as tocontact the conveyor belt rollers 118 such that movement of the conveyorbelt 120 in the direction of belt travel 114 causes rotation of both thedrive rollers and the conveyor belt rollers due to the frictional forcesbetween them. In the orientation shown in FIG. 3, the drive rollers 125rotate in a downstream direction indicated by arrow 136. As aconsequence of that rotation, the conveyor belt rollers 118 are causedto rotate, or are “driven,” about their shafts 138 (i.e., axes ofrotation) in the direction indicated by arrow 140. Accordingly, in FIG.3, the conveyor belt rollers 118 rotate counterclockwise (when viewingthe conveyor belt 102 from its end looking upstream) and would thereforedivert objects supported by the conveyor belt rollers to the left in theorientation of the figure. As is further shown in FIG. 3, each conveyorbelt roller 118 is driven in the above manner by multiple drive rollers125.

As described above, the drive roller modules 106, and therefore thedrive rollers 125, can be pivoted about their central vertical axes 134(FIGS. 2A and 2B) to adjust their angulation relative to the directionof belt travel. The drive rollers 125 can be independently actuated oractuated in synchrony in groups. FIG. 4 illustrates a mechanism forenabling the latter actuation scheme (conveyor belt 102 not shown). Asindicated in FIG. 4, a plurality of rows 142 and columns 144 of driveroller modules 106 are provided having the general configurationdescribed in relation to FIG. 2. As is further indicated in FIG. 4, therows 142 of drive roller modules 106 are linked together with linkingmembers 146 that control the angular orientation of the rollers 125.More particularly, control arms 132 of the drive roller modules 106 arepivotally connected to a linking member 146, which can take the form ofa rod or shaft. By way of example, that connection is made with pins(not shown) that extend through the openings 133 (FIGS. 2A and 2B)provided in the control arms 132 of the drive roller modules 106 andinto aligned openings (not shown) of the linking member 146. When theposition of each drive roller module 106 is fixed relative to itscentral vertical axis 134, for example due to fixation of the lowerportion 141 of the pivot mechanism 137 (FIGS. 2A and 2B), transversedisplacement of the linking members 146 in the directions indicated byarrow 148 causes the rollers 125 to pivot about the central verticalaxes, thereby adjusting their angular orientation.

The linking members 146 can be displaced by any appropriate means. Inembodiments in which multiple linking members 146 are to besimultaneously displaced, and therefore multiple rows of rollers 125 areto be simultaneously pivoted, the linking members can be connected to asingle actuation member 150 that is positioned adjacent either side ofthe conveyor system 100 and pivotally connected to control arms 131 ofan adjacent column 144 of drive roller modules 106. In such a case,longitudinal displacement of the actuation member 150 in the directionsindicated by arrow 151 will cause pivoting of the adjacent column 144 ofdrive roller modules 106, which therefore causes the linking members 146to laterally translate, which, in turn, causes the remaining driveroller modules to pivot.

FIGS. 5A and 5B illustrate the effect of angular adjustment of the driveroller modules 106. Notably, the conveyor belt frame 108 is not shown inFIGS. 5A and 5B for purposes of clarity in describing other componentsof the conveyor system 100. Beginning with FIG. 5A, the drive rollermodules 106 have been pivoted in a counterclockwise direction (when theconveyor belt 102 is viewed from above) to cause counterclockwiserotation (when the conveyor belt is viewed from its end lookingupstream) of the conveyor belt rollers 118, as indicated by arrow 152.Such rotation of the conveyor belt rollers 118 causes diverting actionin a leftward direction in the orientation of FIG. 5A, so as to displacean object O in the direction of arrow 154. In FIG. 5B, however, thedrive roller modules 106 have been pivoted in a clockwise direction(when the conveyor belt 102 is viewed from above) to cause the conveyorbelt rollers 118 to rotate in a clockwise direction (when the conveyorbelt 102 is viewed from its end looking upstream) indicated by arrow 155to cause diverting action in a rightward direction and displace theobject O in the direction of arrow 156.

FIGS. 6A and 6B illustrate the variability of diverting angles possiblewith the drive roller modules 106. As indicated in FIG. 6A, each driveroller module 106 can potentially be taken from a 0° orientation, inwhich the axis of rotation of the roller 125 is perpendicular to thedirection of conveyor belt travel, to some negative angle represented byα. As indicted in FIG. 6B, the drive roller module 106 can also be takenfrom the 0° orientation to some positive angle represented by β. In someembodiments, both α and β can comprise any angle from 0 to 90°, therebyequating to 180° of angular variability. Although such a broad range ofangular variability is possible, conveyor belt speed and limitations ofthe materials used for the drive rollers 125 and conveyor belt rollers118 may limit the range of angular orientations in which roller slip canbe avoided. However, angular ranges of at least approximately −70° to+70° are achievable at conveyor belt speeds of at least 100 ft/min usingknown high-friction surfaces. Notably, the angular displacement of thedrive rollers 125 directly corresponds to the resultant diverting angle.For example, when the drive rollers 125 are oriented 35° clockwise ofthe 0° orientation as shown in FIG. 6A, a 35° diverting angle to theright direction results.

When the drive rollers 125 are positioned in the 0° orientation shown inFIG. 7, in which the axes of rotation of the drive rollers areperpendicular to the direction belt travel and the direction of angularrotation of the drive rollers is in line with the direction of belttravel, the conveyor belt rollers 118 are substantially prevented fromrotating and are therefore “braked.” Accordingly, undesired lateralmovement of objects on the conveyor belt can be prevented, if desired,by controlling the drive roller modules 106, to be placed in the 0°orientation. It is further noted that when the angular orientation ofthe drive rollers 125 is adjusted from the 0° orientation as an initialposition, the conveyor belt rollers 118 can be gradually accelerated inone direction or the other, thereby decreasing or all togetherpreventing the roller slip that can occur when a friction plate orangled rollers suddenly engage the conveyor belt rollers. Gradualacceleration of the conveyor belt rollers 125 also enables relativelyunstable objects to be diverted without tipping over. For instance, ifan object to be diverted is relatively tall and has a relatively smallbase, the object can be gradually accelerated to one side or the otherof the conveyor belt 102 by slowly increasing the angulation of thedrive rollers from the 0° orientation.

In addition to being angularly adjustable, the drive roller modules 106can, optionally, be vertically actuated to engage or disengage the driverollers 125 with conveyor belt rollers 118. Such functionality isdepicted in FIGS. 8A and 8B. In particular, FIG. 8A illustrates thedrive rollers 125 in engagement with the conveyor belt rollers 118,while FIG. 8B illustrates the drive rollers disengaged from the conveyorbelt rollers. Such selective engagement and disengagement can beprovided with an appropriate mechanism (not shown) that lifts the driverollers 125 into contact with the conveyor belt rollers 118 and lowersthe drive rollers out of contact with the conveyor belt rollers.

From the above it can be appreciated that several advantages can beachieved through use of conveyor systems that comprise angularlyadjustable rollers that drive rollers contained within a conveyor belt.For example, objects can be diverted to either side of the conveyorsystem at various angles. In addition, the conveyor belt rollers can bebraked to control object drift across the conveyor belt. Furthermore,the conveyor belt rollers can be accelerated to some desired angularvelocity with virtually no slip.

It is noted that other advantages can also be realized with suchconveyor systems. For example, discrete groups of drive rollers can beoperated in different zones of the conveyor system not only along thedirection of travel of the conveyor belt but also along the width of theconveyor belt through the provision of discrete control mechanisms(e.g., linking members). In such cases, the positions of objects on theconveyor belt can be controlled with great precision by individuallycontrolling the drive rollers of the different zones. In fact, when a“smart” detection and control system is provided, such as animaging-based system, individual objects can be identified and preciselymoved along and/or across the belt, for example to enable desiredordering and/or alignment of the objects on further conveyor belts onwhich the objects are to be placed.

Turning to FIG. 9, illustrated is a second embodiment of a portion of aconveyor system 200. As indicated in that figure, the conveyor system200 is similar in several ways to the conveyor system 100 shown inFIG. 1. Therefore, the conveyor system 200 generally comprises aconveyor belt 202 that includes a plurality of longitudinally orientedfree-spinning conveyor belt rollers 204. The conveyor belt 202 travelsin a direction of belt travel identified by arrow 206. In addition, thesystem 200 comprises a plurality of free-spinning angularly adjustabledrive rollers 208. In the system 200, however, the drive rollers 208 areelongated, or “longitudinal,” rollers instead of caster rollers. In theembodiment shown in FIG. 9, the drive rollers 206 are longer than theconveyor belt 202 is wide.

FIGS. 10A-10C illustrate angular adjustment of the drive rollers 208relative to the conveyor belt 202. In particular, assuming a conveyorbelt direction of travel indicated by arrow 206, FIG. 10A illustrates anangulation of the drive rollers 208 that results in the diverting ofobjects to the left, FIG. 10B illustrates the “braking” orientation ofthe drive rollers, and FIG. 10C illustrates an angulation of the driverrollers that results in the diverting of objects to the right.

As with the conveyor system 100, the drive rollers 208 can be angularlyadjusted using a variety of adjustment mechanisms. FIGS. 11A and 11Billustrate one such mechanism (conveyor belt not shown for purposes ofclarity). As shown in those figures, the drive rollers 208 can bepivotally supported by a rectangular frame 210 comprising multiple framemembers 212 that are pivotally connected to each other at pivot joints214 located at corners of the frame. By way of example, each pivot joint214 is formed by leaves of the frame members 212 that interleave witheach other and are secured together with a pin or shaft (not shown).With such a configuration, orientation of the frame 210 can be changedfrom the orthogonal orientation shown in FIG. 11A, in which the framemembers 212 form approximately 90° angles at each of the corners of theframe, to another orientation at which two acute angles and two obtuseangles are formed at the frame corners, as shown in FIG. 11B, therebyplacing the frame into a parallelogram shape. In the orthogonalorientation of FIG. 11A, the drive rollers 208 are aligned so as to beperpendicular to the direction of belt, as indicated in FIG. 10B.Therefore, the orthogonal orientation of FIG. 11A is the brakingorientation. At other orientations, however, such as that indicated inFIG. 11B, the drive rollers 208 are oriented such that they arepositioned at an angle relative to the direction of belt travel, therebyproviding the diverting function.

Each drive roller 208 is supported at both ends by a joint that permitsthe change in orientation as well as free rotation. With reference tothe detail view of FIG. 12, each drive roller 208 can, for example, besupported by a shaft 215 having “eye” connectors 216 configured toreceive a pin 218 that extends through a support bracket 220 that ismounted to a frame member 212.

Returning to FIGS. 11A and 11B, the frame 210 can be manipulated in themanner described above by, for example, using an actuator 222. In theembodiment shown in FIGS. 11A and 11B, the actuator 222 comprises apiston member having a piston body 224 from which a piston arm 226 canbe extended, for instance under the influence of hydraulic or pneumaticpressure. Both the piston body 224 and the piston arm 226 are pivotallyconnected to adjacent frame members 212 with mounting brackets 228. Withsuch an arrangement, retraction of the piston arm 226 into the pistonbody 224 results in angular adjustment of the drive rollers 208 in afirst angular direction, while extension of the piston arm from thepiston body results in angular adjustment of the drive rollers in asecond, opposite angular direction. Such manipulation is evident fromFIGS. 11A and 11B. In particular, FIG. 11A illustrates a first extent ofextension of the piston arm 226 from the piston body 224 and a firstorientation of the drive rollers 208, while FIG. 11B illustrates asecond (greater) extent of extension of the piston arm from the pistonbody and a second orientation of the drive rollers. Through appropriateextension and retraction of the piston arm 226, the orientation of thedrive rollers 208 can be precisely controlled and diverting of objectscan be achieved to either side of the conveyor belt 202 at variousdiverting angles as depicted in FIGS. 10A-10C.

An exploded view of a portion of another version of a diverting conveyorsystem 300 having a different roller drive mechanism is shown in FIG.13. A conveyor belt 302 has a plurality of cylindrical rollers 304mounted on axles (not shown) aligned longitudinally in the direction ofbelt travel 306. The belt is constructed of a series of rows 307 of oneor more belt modules, only one row of which is shown in FIG. 13,connected side to side and end to end at hinge joints into an endlessbelt loop advancing along a portion of a conveyor carryway 309 in thedirection of belt travel. The belt rollers are supported atop an arrayof drive rollers 308 along a portion of the carryway. Narrow rails 310upstream and downstream of the drive-roller array support the belt alongthe remainder of the carryway. The narrow rails, topped with UHMWwearstrips 312, support the underside of the belt between adjacentrollers.

The rails are mounted on a carryway pan 314, which is itself mounted ina conveyor frame (not shown). The pan is perforated with a plurality ofcircular openings 316 arranged in longitudinal columns 318 and lateralrows 319. The columns of openings are laterally aligned with the lateralpositions of the belt rollers. Each opening rotatably receives acartridge 320 supporting a freely rotatable drive roller 308, whichengages the belt rollers in the corresponding column as the beltadvances in the direction of belt travel. The rolling contact betweenthe belt rollers and the drive rollers causes them both to roll on eachother and rotate as long as their axis are oblique to each other.

As shown in FIG. 14, the drive roller cartridge 320 includes a retainerring 322 with diametrically opposite holes 324, 325 supporting the endsof an axle 326 received in a bore 327 in the drive roller 308. One ofthe holes 324 can be a through hole through which the axle can beinserted into the cartridge and the drive roller, and the other hole 325can have a blind end forming an end stop for the axle. In this way, thedrive roller is retained in the cartridge along a fixed axis with asalient portion of the roller protruding beyond the top of the retainerring. Extending downward from the retainer ring encircling the driveroller is an upper journal stem 328 having a cylindrical outer peripheryindented inward from the ring, which forms a shoulder 330 between theperipheries of the ring and the stem. A lower journal stem 332 distalfrom the retainer ring has a smaller diameter than the upper journalstem. The periphery of the lower journal stem is indented inward of theperiphery of the upper journal stem. A cartridge gear 334 is disposedbetween the upper stem and the lower stem. The cartridge gear ispreferably a spur gear with peripheral teeth 336 whose tips do notextend past the periphery of the upper journal stem.

The cartridges 320 are received in the openings 316 in the carryway panas shown in FIG. 13. The walls of the openings form bearing surfaces 338against which the upper journal stems can rotate. Because the diameterof the retainer rings exceeds the diameter of the openings, the ring'sshoulder 330 rests atop the carryway pan with the smaller-diameter stemsand gear portions suspended below.

A gear plate 340 is movably positioned below the carryway pan. Actuatorgears in the form of rack gears 342 are disposed on the gear plate. Eachrack gear is positioned to engage the teeth of one of the cartridgegears to form a rack-and-pinion system that can rotate the cartridges inunison as the gear plate is translated. The gear plate has openings 344elongated in the direction of belt travel. The elongated openings arebounded on one side by a linear array of teeth 346 forming a rack gear.Each elongated opening is positioned below one of the openings 316 inthe carryway pan. The lower journal stem extends through the elongatedopenings in the gear plate, which is sandwiched between two otherplates: the carryway pan 314 and a bottom plate 348. The bottom plate,which is stationarily affixed to a portion of the conveyor frame 350,has a plurality of openings 352 vertically aligned with, but having asmaller diameter than, the openings in the carryway pan. The openings352 are sized to rotatably receive the lower journal stems 332 of thecartridges. This helps align the upper and lower support plates tofacilitate assembly of the roller drive mechanism and also confines therotatable cartridges in rotation on fixed vertical axes.

Confronting spacer pads 354 on the top of the bottom plate 348 and onthe bottom of the top plate 314 meet to maintain the proper spacingbetween the two plates to accommodate the movable gear plate 340. Someof the elongated openings 344′ in the gear plate are joined byintermediate slots 356. Rollers 358 in the slot portions arerotationally mounted on pins 360 extending downward from the bottom ofthe top plate. The distal ends of the pins are received in sockets 362in the bottom plate. The rollers 358 bear on the sides of the slots asthe gear plate is translated relative to the top and bottom plates.

The gear plate is translated by a linear actuator 364, such as an aircylinder, as shown in FIG. 15. One end of the actuator is attached to amounting bracket 366 suspended from the bottom of the top plate, orcarryway pan 314, by a clevis and tie rod 368. The extension of anextension rod 370 from the other end of the actuator is selectable. Thedistal end of the extension rod is connected by a clevis and tie rod 372to a pivot bracket 374 suspended from the bottom of the gear plate 340.The extension rod translates the gear plate, the rod's extensiondetermining the position of the gear plate and the orientation of thedrive rollers. Shims 376 under the mounting bracket 366 are used toaccount for the offset between the bottom of the carryway and the top ofthe gear plate.

The operation of the diverting conveyor system is illustrated in FIGS.16A and 16B. In FIG. 16A, the gear plate 340 is shown translated to oneextreme position in which the drive roller cartridges 320 are positionedat the far right of the elongated slots 344. With the cartridges rotatedto this position, the axes of rotation 378 of the drive rollers 308 forma counter clockwise acute angle γ measured from the direction of belttravel 306. As the conveyor belt 302 advances in the direction of belttravel, the drive rollers in this orientation rotate in the direction ofarrow 380 and the engaged belt rollers in the direction of arrow 382 todirect conveyed objects towards the top of FIG. 16A. When the gear plateis translated over its range to the opposite extreme with the cartridgespositioned at the far left of the elongated slots in FIG. 16B, the axesof rotation 378 of the drive rollers form a clockwise acute angle γ′measured from the direction of belt travel. In this orientation, thedrive rollers rotate in the direction of arrow 381, and the belt rollersrotate in the direction of arrow 383 to push conveyed objects toward thebottom of FIG. 16B-opposite to the diverting direction of FIG. 16A.

While particular embodiments have been disclosed in detail in theforegoing description and drawings for purposes of example, it will beunderstood by those skilled in the art that variations and modificationsthereof can be made without departing from the scope of the disclosure.In one such variation, the lower stems of the drive-roller cartridgescan have hollows at their bottoms, and the openings in the bottom platereplaced by posts extending into the hollows on which the cartridgesrotate.

1. A conveyor system comprising: a conveyor belt having a pluralityconveyor belt rollers configured to divert objects on the conveyor beltas the conveyor belt advances; and a roller drive mechanism including: aplurality of rotatable cartridges, each cartridge having a cartridgegear and a freely rotatable drive roller that engages the conveyor beltrollers from below the conveyor belt; a plurality of actuator gears,each engaged with one of the cartridge gears, to rotate the cartridgesto change the orientations of the rotatable drive rollers with respectto the conveyor belt rollers; and an actuator configured to move theplurality of actuator gears to rotate the cartridges between a firstorientation in which the engagement between the drive rollers and theconveyor belt rollers causes the conveyor belt rollers to rotate in afirst direction as the conveyor belt advances and a second orientationin which the engagement between the drive rollers and the conveyor beltrollers causes the conveyor belt rollers to rotate in an opposite seconddirection.
 2. The conveyor system of claim 1 comprising a plateincluding rack gears forming the actuator gears and wherein the actuatoris coupled to the plate to translate the plate between a first positionand a second position and rotate the cartridges in unison.
 3. Theconveyor system of claim 1 wherein the actuator gears are rack gears andwherein the cartridge gears are pinions that engage the rack gears. 4.The conveyor system of claim 1 wherein each of the cartridges furthercomprises: an axle for the drive roller; a retainer ring encircling thedrive roller and supporting the ends of the axle in the cartridge, theretainer ring having a shoulder; an upper journal stem connected to theretainer ring and having a cylindrical periphery inward of the shoulder;a lower journal stem having a cylindrical periphery indented inward ofthe cylindrical periphery of the upper journal stem; a pinion disposedbetween the upper journal stem and the lower journal stem and havingperipheral teeth with tips extending outward no farther than theperiphery of the upper journal stem.
 5. The conveyor system of claim 4comprising: a top plate having a plurality of circular openings sized toform bearings for the first journal stems of the cartridges with theshoulders of the cartridges sitting atop the top plate; a bottom platehaving a plurality of circular openings aligned with the circularopenings in the top plate and sized to form bearings for the secondjournal stems; wherein the roller drive mechanism includes atranslatable gear plate disposed between the top plate and the bottomplate, the actuator gears positioned on the gear plate to engage thepinions and rotate the cartridges as the gear plate is translated.
 6. Aconveyor system comprising: a conveyor belt having a plurality conveyorbelt rollers arranged to rotate on fixed axes aligned in a direction ofbelt travel; a carryway pan underlying the conveyor belt and having aplurality of openings; a plurality of cartridges rotatably supported inthe openings, each cartridge including a freely rotatable drive rollerretained in position to engage the conveyor belt rollers from below theconveyor belt and a cartridge gear disposed below the carryway pan; anarray of actuator gears positioned to engage the cartridge gears; anactuator coupled to the array of actuator gears to actuate the gears torotate the cartridges and change the angle of engagement between thedrive rollers and the conveyor belt rollers.
 7. The conveyor system ofclaim 6 wherein the actuator gears and the cartridge gears comprise arack-and-pinion system.
 8. The conveyor system of claim 6 wherein thearray of actuator gears comprises a plate having a plurality ofopenings, each opening bounded on one side by a linear array of gearteeth.
 9. The conveyor system of claim 6 wherein each cartridge has adistal lower stem, the conveyor system further comprising a stationarybottom plate rotatably retaining the lower stem of the cartridge inplace.
 10. The conveyor system of claim 9 wherein the stationary bottomplate includes a plurality of openings rotatably receiving the lowerstems of the cartridges.
 11. The conveyor system of claim 6 wherein theactuator is a linear actuator that translates the array of actuatorgears to rotate the cartridges.
 12. The conveyor system of claim 6wherein the actuator has a range of translation capable of changing theangle of engagement between a first angle causing the conveyor beltrollers to rotate in a first direction and a second angle causing theconveyor belt rollers to rotate in an opposite second direction.
 13. Theconveyor system of claim 6 comprising a drive roller axle retained inthe cartridge and defining the axis of rotation of the roller.
 14. Theconveyor system of claim 6 wherein each of the cartridges furthercomprises: a retainer rotatably retaining the drive roller with asalient portion of the drive roller extending above the retainer; anupper journal stem connected to the retainer and having a cylindricalperiphery received in one of the openings; a pinion disposed below theupper journal stem to engage one of the actuating gears.
 15. A conveyorsystem comprising: a conveyor belt advancing longitudinally in adirection of belt travel and having a plurality of conveyor belt rollersarranged in lateral rows and longitudinal columns and rotatable on fixedlongitudinal axes; a roller drive mechanism underlying the conveyorbelt, including: a support plate having a plurality of openings arrangedin columns aligned with the columns of conveyor belt rollers; aplurality of cartridges rotatably received in the openings and havingcartridge gears and drive rollers supported in position to engage theconveyor belt rollers; a movable gear plate having a plurality ofactuator gears, each engaged with one of the cartridge gears to rotatethe cartridges and the drive rollers as the gear plate is moved.
 16. Theconveyor system of claim 15 further comprising a linear actuator coupledto the gear plate to translate the gear plate to rotate the cartridges.17. The conveyor system of claim 15 wherein the support plate isdisposed between the conveyor belt and the gear plate.
 18. The conveyorsystem of claim 15 wherein each cartridge has a lower stem distal fromthe drive roller, the conveyor system further comprising a stationarybottom plate rotatably retaining the lower stem of the cartridge inplace.
 19. The conveyor system of claim 15 wherein each cartridgeincludes: an axle for the drive roller; a retainer ring encircling thedrive roller and retaining the ends of the axle; an upper journal stemconnected to the retainer ring and having a cylindrical peripheryindented inward of the retainer ring; a lower journal stem having acylindrical periphery indented inward of the cylindrical periphery ofthe upper journal stem; a pinion disposed between the upper journal stemand the lower journal stem and having peripheral teeth with tipsextending outward no farther than the periphery of the upper journalstem.
 20. The conveyor system of claim 15 wherein the actuator gears andthe cartridge gears comprise a rack-and-pinion system.